title: Ultrasmooth silver thin film electrodes with high polar liquid wettability for OLED microcavity application.
abstract: For a lab-on-chip application, we fabricate a blue bottom emitting strong microcavity organic light emitting diode (OLED), using very smooth and optically thin (25 nm) silver film as anode on a glass substrate. To improve the hole injection in the OLED device, PEDOT-PSS (poly(3,4-ethylenedioxythiophene)-poly(styrene sulfonic acid)) has been used, so the silver anode must present not only a very smooth surface but also a strong adherence on the glass and a high wettability to allow a good PEDOT-PSS spin coating deposition. To obtain these physical properties, different 5 nm thick nucleation layers (germanium, chromium, and hydrogenated amorphous carbon) have been used to grow the silver thin films by e-beam deposition. The Ge/Ag bilayer presents all the desired properties: this bilayer, investigated by ellipsometry, optical profilometry, contact angle measurements, and XPS analysis, highlights an ultrasmooth surface correlated with the film growth mode and a high wettability related to its surface chemical composition.
authors.affiliation: Université de Toulouse, UPS, INPT, LAPLACE (Laboratoire Plasma et Conversion d'Energie), 118 route de Narbonne, F-31062 Toulouse cedex 9, France.
authors.forename: Cristina
authors.initials: C
authors.lastname: Cioarec
authors.forename: Patrizia
authors.initials: P
authors.lastname: Melpignano
authors.forename: Nicolas
authors.initials: N
authors.lastname: Gherardi
authors.forename: Richard
authors.initials: R
authors.lastname: Clergereaux
authors.forename: Christina
authors.initials: C
authors.lastname: Villeneuve